Are we losing our most valuable soils to urban expansion?

Recently, TV3's NewsHub alerted New Zealanders to the loss of some of our best quality soils to urban expansion [watch the story here].

There has been a tendency in New Zealand to think of ourselves as a country rich with fertile, soils, capable of producing food almost without limit. But in fact a mere five percent of our soils have the fertility required to produce vegetables and other high-value crops. Unfortunately much of this five percent is concentrated around urban areas where there is an ongoing pressure for land for urban expansion.

NewsHub's Isobel Ewing focused her story on Pukekohe, long known as New Zealand's most important foodbasket. Owing to proximity to land-hungry Auckland, its best horticultural land is coming under increasing pressure for housing.

This tension between urban expansion and the impetus to protect our best, most productive soils, is a perennial one. It became a major concern for planners back in the 1970s. The protection of these soils was seen as so critical to the future of the country that not one, but two, soil-related matters were added as "Matters of National Importance" to the Town and Country Planning Act 1953, the all-pervasive planning law at the time.

These matters, which district councils were required to have regard to in all matters of planning, were “the avoidance of encroachment of urban development on, and the protection of, land having a high actual or potential for the production of food” and “the prevention of sporadic urban sub-division and development in rural areas”.

These matters were stripped out when the Resource Management Act was enacted in 1991. Since then there has been a reluctance on the part of successive governments to put any national policy in place to protect our highest value soils. Instead it has been left to regional governments to fight that fight in their respective communities, if they have the capacity or inclination.

So it seems we have gone backwards when it comes to protecting one of our most valuable resources. This seems strange in a country that prides itself on its agricultural capability. Given our geographical isolation from other food-producing countries, it would also be assumed that we would want to be as self-reliant as possible when it comes to food, in a world increasingly wracked by tension over resources and ideologies. Perhaps we are putting our faith in technology to satisfy our food needs in the future when all our best soils are under concrete pads and manicured lawns.

A 3D-printed cabbage, anyone?

Images top: Coming to a store near you! These 3-D printed carrots are currently being served to resthome residents in Germany. Apparently they are easier on the dentures. Stuff.co.nz. Above: A cabbage crop at Otaki, ca 1945. Alexander Turnbull Library.